1. Field of the Invention
The present invention relates to an ink-jet printhead, and more particularly, to a bubble-jet type ink-jet printhead and manufacturing method thereof.
2. Description of the Related Art
The ink ejection mechanisms of an ink-jet printer are largely categorized into two types: an electro-thermal transducer type (bubble-jet type) in which a heat source consisting of resistive heating elements is employed to form a bubble in ink causing ink droplets to be ejected, and an electro-mechanical transducer type in which a piezoelectric crystal bends to change the volume of ink causing ink droplets to be expelled.
An ink-jet printhead having this bubble-jet type ink ejector needs to meet the following conditions. First, a simplified manufacturing procedure, low manufacturing cost, and high volume production must be offered. Second, to produce high quality color images, creation of satellite droplets that trail ejected main droplets must be prevented. Third, when ink is ejected from one nozzle or ink is refilled into an ink chamber after ink ejection, cross-talk with adjacent nozzles from which no ink is ejected must be prevented. To this end, a back flow of ink in the opposite direction of a nozzle must be avoided during ink ejection. Another heater shown in FIGS. 1A and 1B is provided for this purpose. Fourth, for a high speed print, a cycle beginning with ink ejection ending with ink refill must be as short as possible.
However, the above conditions tend to conflict with one another, and furthermore the performance of an ink-jet printhead is closely associated with the construction of an ink chamber, ink channel, and heater, types of formation and expansion of bubbles, and the relative size of each element.
In efforts to overcome problems with the above requirements, ink-jet print heads having a variety of structures have been proposed in U.S. Pat. Nos. 4,339,762; 4,882,595; 5,760,804; 4,847,630; and 5,850,241, European Patent No.317,171, and Fan-Gang Tseng, Chang-Jin Kim, and Chih-Ming Ho, “A Novel Micoinjector with Virtual Chamber Neck’, IEEE MEMS '98, pp. 57-62. However, ink-jet printheads proposed in the above patents and literature may satisfy some of the aforementioned requirements but not completely provide an improved ink-jet printing approach. Thus, further improvements for an ink-jet printhead remain to be required.